LHS 3844 b
LHS 3844 b is a super-Earth orbiting the M4.5-M5.0 star LHS 3844 in the constellation Indus. It lies about 49 light-years from Earth and was discovered in 2019 using the transit method.
How Big Is LHS 3844 b?
LHS 3844 b has a radius of 1.29 times that of Earth. Its mass is 2.4 times that of Earth, giving it a density of 6.15 g/cm³ — comparable to rocky planets like Earth (5.51 g/cm³).
Is LHS 3844 b in the Habitable Zone?
LHS 3844 b orbits inside the inner edge of the habitable zone of LHS 3844. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of LHS 3844: 0.043–0.113 AU (conservative: 0.054–0.108 AU), per Kopparapu et al. (2014). Earth orbits the Sun at 1 AU.
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Temperature on LHS 3844 b
The equilibrium temperature of LHS 3844 b is about 816 K (543 °C) — hot enough to melt many metals. This estimate ignores any atmosphere, which could change surface temperatures dramatically — Earth's greenhouse effect adds about 33 °C. It receives 73.67 times the stellar energy that Earth gets from the Sun.
Orbit and Year Length
A year on LHS 3844 b — one full orbit around LHS 3844 — lasts just 11.1 hours, shorter than Mercury's 88-day year. It orbits at an average distance of 0.006 AU — closer to its star than Mercury is to the Sun.
How Was LHS 3844 b Discovered?
LHS 3844 b was discovered in 2019 using the transit method, with observations from Transiting Exoplanet Survey Satellite (TESS).
The transit method watches a star for the tiny, regular dip in brightness that occurs when a planet crosses in front of it. The depth and timing of these dips reveal the planet's size and orbital period.
How Far Away Is LHS 3844 b?
LHS 3844 b is 48.5 light-years (14.9 parsecs) from Earth. Light arriving here tonight left the planet around the year 1978. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 853,600 years to make the journey.
Earth Similarity Index
The Earth Similarity Index (ESI) scores how physically similar a planet is to Earth, from 0 to 1, based on radius, density, escape velocity and surface temperature. LHS 3844 b scores 0.31, ranking #1,218 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: LHS 3844
LHS 3844
- Spectral type
- M4.5-M5.0
- Surface temperature
- 3,080 K (Sun: 5,772 K)
- Mass
- 0.15 M☉
- Radius
- 0.19 R☉
- Luminosity
- 0.0027 L☉
- Age
- 7.8 billion years (Sun: 4.6)
Planetary System
LHS 3844 b is the only planet known to orbit LHS 3844 so far.
LHS 3844 b — Complete Data
| Radius | 1.286 Earth radii (0.115 Jupiter radii) |
|---|---|
| Mass | 2.37 Earth masses (0.007 Jupiter masses) |
| Density | 6.15 g/cm³ (Earth: 5.51) |
| Orbital period | 0.46 days |
| Orbital distance | 0.006 AU |
| Equilibrium temperature | 816 K (543 °C) |
| Stellar irradiation | 73.67× Earth |
| Earth Similarity Index | 0.31 |
| Distance from Earth | 48.5 light-years (14.9 parsecs) |
| Constellation | Indus |
| Discovery method | Transit |
| Discovery facility | Transiting Exoplanet Survey Satellite (TESS) |
| Discovery year | 2019 |
Data: NASA Exoplanet Archive, last updated 2026-04-16. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About LHS 3844 b
Is LHS 3844 b habitable?
No — LHS 3844 b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is LHS 3844 b?
LHS 3844 b is about 49 light-years from Earth in the constellation Indus. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 853,600 years to get there.
How big is LHS 3844 b compared to Earth?
LHS 3844 b has 1.29 times the radius of Earth and about 2.4 times its mass.
How long is a year on LHS 3844 b?
One orbit around LHS 3844 takes 0.5 Earth days — short enough that 789 of its years would fit into one Earth year.
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